DESCRIPTION (Adapted from Applican't Abstract): Dysthymic Disorder (DD) is a fairly prevalent condition with substantial social costs. As a nosological construct, it is defined and distinguished from Major Depressive Disorder (MDD) primarily on the bases of longitudinal course. Ironically, however, prospective data on the long-term course of DD are extremely limited. The present proposal seeks funding to complete the last five years of a then-year naturalistic follow-up study of DD, with follow-up evaluations being completed at 30 months intervals. Subjects include 97 outpatients who met DSM-III-R criteria for primary, early-onset dysthymia at entry into the study, and a comparison group of 45 outpatients with non-chronic (or episodic) major depression. Baseline and follow-up assessments include structured diagnostic interviews assessing Axis I and Axis II disorders conducted blind to the baseline evaluation, a comprehensive battery of self-report inventories, interviews with knowledgeable informants, and review of medical records. Attrition over the first five years of follow-up has been relatively low. The study addresses five major issues: (1) the diagnostic stability of DD; (2) the long-term naturalistic course of DD; (3) clinical, Psychosocial, and familial predictors of course and outcome; (4) the stability of comorbid anxiety and personality disorders, and their relationship with DD over time; and (5) the long-term course of social adjustment in DD.